Question 1194288
A mother is three times as old as her son. In 18 years time, she will be twice as old as her son. How old is she now? 
<pre>Let the mother's age be M
As the mother is thrice the son's age, son's age is {{{M/3}}}
We then get: {{{matrix(4,3, M + 18, "=", 2(M/3 + 18), M + 18, "=", 2M/3 + 36, M, "=", 2M/3 + 36 - 18, M, "=", 2M/3 + 18)}}}
                 3M = 2M + 54 ------- Multiplying by LCD, 3
            3M - 2M = 54
       Mother, or M, is <font size = 4><font color = red><b>54 years-old</font></font></b></pre>